Britney Spears' Sons Sean and Jayden Look All Grown Up -- See the Pic!

The proud mom shared two side-by-side photos of her boys, 11-year-old Sean and 10-year-old Jayden, on Thursday, wearing plaid shirts as they sat on their decadent staircase decked out in Christmas decorations.

The "Slumber Party" singer frequently posts photos of big moments in Sean and Jayden's lives. The last one she shared of the lookalike siblings was in mid-November, when the duo met Los Angeles Rams wide receiver Kenny Britt.

Spears also shares lots of Instagram pics of her crazy fit bod. This week alone, she showed off two impressive stretching feats. Both showed the pop star upside down with her feet up in the air, giving us a clear view of her toned abs and legs.